1. Field of the Disclosure
The present disclosure relates to a fuel cell stack configured to allow easy replacement of a faulty membrane-electrode assembly. A replacement device for a membrane-electrode assembly of the fuel cell stack is also disclosed.
2. Description of the Related Technology
A fuel cell system includes a fuel cell stack configured for generating electric energy by an electrochemical reaction between a fuel (hydrocarbon fuel, pure hydrogen, or reformed gas rich in hydrogen) and an oxidant (air or pure oxygen). A direct oxidation fuel cell uses a liquid or gaseous hydrocarbon fuel. A polymer electrode fuel cell uses pure hydrogen or a reformed gas rich in hydrogen as a fuel.
The fuel cell stack includes membrane-electrode assemblies, separators interposed between the membrane-electrode assemblies, the separators configured to supply a fuel and an oxidant to the membrane-electrode assemblies, and a pair of end plates located outside the separators. The fuel cell stack is integrally assembled by fastening members. Each of the fastening members may consist of a tie bolt penetrating at least four corners of the fuel cell stack and a fixing nut fastened to an end of the tie bolt on the outside of the end plates and tightening the tie bolt.
If a problem occurs in one of the membrane-electrode assemblies of the fuel cell stack, the overall performance of the fuel cell stack is reduced. However, a single problematic membrane-electrode assembly cannot be easily identified and taken out of the fuel cell stack without testing each individual membrane-electrode assembly before assembling the fuel cell stack. Further, if a problem occurs with a specific membrane-electrode assembly after assembling the fuel cell stack, the entire membrane-electrode assembly has to be replaced. That is, the entire fuel cell stack must be disassembled and then reassembled in a cumbersome replacement process. Moreover, because dissembling and reassembling the fuel cell stack may damage other membrane-electrode assemblies the replacement operation must be carried out delicately.